The word 'broadcast' is one of the English language's most successful metaphorical transfers — a term born in the dirt of eighteenth-century agriculture that was lifted, almost unchanged, into the vocabulary of twentieth-century technology, where it became one of the defining words of the media age.
The agricultural sense came first. To 'broadcast' seed was to sow by hand, walking across a plowed field and casting handfuls of grain in wide arcs so that the seed fell broadly and relatively evenly across the soil. This was the oldest method of sowing — older than the seed drill, older than row planting — and the compound 'broadcast' described both the method and its characteristic gesture. 'Broad' (from Old English 'brād,' wide) and 'cast' (from Old Norse 'kasta,' to throw) together captured the essential action: a wide throw, a generous scattering.
The first known written use in this agricultural sense dates to 1767, though the practice it describes is ancient. The word could function as verb ('to broadcast the wheat'), adjective ('broadcast sowing'), and noun ('sown by broadcast'). It was a working farmer's term, practical and concrete, with no hint of the technological afterlife that awaited it.
The metaphorical transfer happened in the early 1920s, when commercial radio transmission was beginning in the United States and Europe. The pioneers of radio needed vocabulary to describe what their new technology did, and they found it in the fields. A radio transmitter, like a farmer broadcasting seed, sent its signal out in all directions simultaneously, and whoever happened to be within range could receive it. The analogy was almost perfect
The word appeared in a radio context as early as 1921 and was standard usage by the mid-1920s. 'Broadcasting' became the name for the entire industry of radio (and later television) transmission. The BBC — the British Broadcasting Corporation, founded in 1922 — built the word into its very name. A 'broadcaster' was a person or organization that transmitted programmes, and a 'broadcast' was the programme itself or the act of transmitting it.
The speed with which the agricultural metaphor was adopted is remarkable. Within a decade, the media sense had almost entirely eclipsed the farming sense in everyday usage. Most English speakers today are entirely unaware that 'broadcast' ever had anything to do with agriculture, and the idea of broadcasting seed sounds like a metaphorical extension of the radio sense rather than the other way around.
The word's success spawned a family of media-specific compounds and derivatives. 'Narrowcast' (1930s) described transmission aimed at a specific, limited audience — the opposite of broadcasting. 'Simulcast' (1948) combined 'simultaneous' and 'broadcast' for programmes transmitted on multiple channels at once. 'Webcast' (1990s) transferred the concept to internet streaming. And 'podcast' (2004), coined by journalist Ben Hammersley in a Guardian article, blended Apple's 'iPod' with 'broadcast' to name audio programmes distributed via the internet — creating a word that layers a twenty-first-century brand name onto an Old Norse verb and an Old English adjective.
Grammatically, 'broadcast' is notable for its irregular past tense. Like 'cast' itself, 'broadcast' typically does not change form in the past tense: 'she broadcast the news yesterday.' The form 'broadcasted' exists and is gaining ground, particularly in American English, but many speakers and style guides still prefer the unchanged form. This resistance to regularization connects 'broadcast' to its Old Norse heritage — 'kasta' belonged to a class of verbs that did not mark the past tense with a dental suffix.
The metaphor embedded in 'broadcast' has also shaped how English speakers think about communication itself. We speak of 'reaching a wide audience,' 'scattering information,' and 'spreading the word' — all metaphors of agricultural distribution applied to communication. The idea that information is something sown, scattered, and harvested has deep roots in English (the parable of the sower in the King James Bible uses exactly this imagery), and 'broadcast' crystallized that tradition into a single word that bridges the pre-industrial and the electronic worlds.